Apparatus



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,F. E. NORTON.

REFRIGERATING APPARATUS.

APPLICATION FILED JAN. 26. 1918.

Patented May 30, 1922.

InrJenor UNITED STATES PATENT OFFICE.

FRED E. NORTON, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO JEFFERIES-NORTON REFRIGERATING APPARATUS.

Specification of Letters Patent.

Patented May 30, 1922.

Original application filed March 3, 1915, Serial No. 11,850. Divided and this application filed January To aZZ whom it may concern: I

Be it known that I, FRED E. Non'ron, a citizen of the United States, residing at V Vorccster, in the county of lVorcester and Commonwealth of Massachusetts, have invented a new and useful Improvement in a Refrigerating Apparatus, of which the following, together with the accompanying drawings, is a specification.

The present application is a division of my prior application covering a process of refrigeration. Serial No. 11.850, l'ilcd .v'larch 3, 1915, and issued as U. S. Letters Patent No. 1,261,815, dated April 30. 1918. The present invention in common with that of my above designated patent, relates in general to the art of refrigeration, and has particular reference to the attainment of extremely low temperatures by the use of a gaseous working fluid. The low temperatures thus attained may be used. if desired, in securing extreme refrigerative efforts, or the invention may be utilized ior the purpose of lirpiefying. in whole or in part. the gaseous working fluid. and i1 desired, this liquefaction, it the gas be amixed gas, may be employed in connection with suitable distillation agencies to effect the separation 05 the gas into its constituent elements. lilorcover. as will be shown. the invention may with advantage be used for the cheap and e'l'hcien't production of power in aform available for the delivery of useful work.

The present invention contemplates the attainment of marked improvements in ctiiciency and capacity over refrigeration systems heretofore known: the principles of the invention are fully set forth in the following description and pointed out in the annexed claims, reference being had to the accompanying drawings, in which- Figure 1 is a diagrammatic. represcntm tion of an arrangement of apparatus in accordance with my invention.

Figure 2 is a fragmentary view of the same apparatus, on an enlarged scale.

Figure is a View similar to Fig. 2. illustrating, diagrammatically. a modification of said apparatus.

Like reference characters parts in the different figures.

it is to be clearly understood, however. that my invention is not in any way confined to the herein described or any particular arreter to like Serial No. 213,888.

rangement of apparatus, nor to the herein described methods of operating the same, except in so far as specified in the annexed claims; the drawings and description being illustrative merely of one way of utilizing the broadly new principles of my invention.

As heretofore practiced, systems of this class, which may or may not involve the complete liquefaction of the working fluid, depending upon the ultimate purpose to which the refrigeration is to be applied, have shown extremely low eliiciency and capacity for refrigeration, by reason of the demands made upon the external cooling agency in attaining the desired low temperatures, such systems. therefore, requiring large expenditures of power for supplying the necessary refrigerative effect. In such prior systems it is customary to cool the incoming compressed working fluid by interchange of heat with cold expanded working fluid flowing counter-current thereto. thereby bringing said incoming fluid into a. condition to be liquefied by the cooling effect of the external cooling agency. It is known that the specific heat, and hence the heat absorbing capacity, of a cold compressed gas is greater, the higher the pressure upon said gas; in such prior systems, therefore, it is apparent that the cooling effect oi. the expanded low pressure gas flowing countercurrent to the incoming highly compressed gas, is subject to serious limitations by reason of this phenomenon; in other words. it is manifestly impossible for a given weight of incomingworking fluid under high pressure. to be cooled through the same range of temperature as the same weight of outgoing low pressure gas is warmed, by the interchange of heat above described. As a result. this deficiency in cooling effect must be compensated for by the external cooling agency. greatly reducing the latters ability to produce useful or available refrigerative efi'ect.

It has heretofore been proposed, in systems of this class. to retain the outgoing work- .ing fluid under pressure. and even to increase its pressure over the pressure under which it was liquefied, as fully set forth in the process described in the copending application of E. A. TV. Jefl'erics. Serial No. 4,536, filed January 26, 1915, whereby said outgoing fluid after leaving the system is capable of efiiciently absorbing external heat, for the erformance of useful work by expansion. owever, since the external cooling agency, which is essential to the process of' said copending application, is alone relied upon to effect the liquefaction of the incoming gaseous fluid, i. e., to remove its latent heat, said liquefaction must be accomplished under such a high pressure, that an increase of pressure suflicient to yield any considerable advantage from the above described specific heat phenomenon is both impracticable and undesirable.

According to the present invention the difficulties above enumerated are overcome by the employment of certain steps designed to effect the extraction of latent heat from the incoming working fluid, whereby a great part of the burden of cooling heretofore im posed on the external cooling agency is relieved, and the liquefaction ot the i coming fluid can be accomplished under a relatively low pressure. As a result of the above, a considerable pressure increase upon the outgoing portion of the working fluid is permissible; the consequently relatively high heat absorbing capacity of the outgoing fluid can be utilized for the extraction of heat from the low pressure incoming fluid and for absorbing the inlealrage of external heat, and the efficiency and capacity of the entire system thus correspondingly increased.

The application of these principles to the attainment of the objects mentioned above is illustrated by way of example in the apparatus of the accompanying drawings, wherein is shown, diagrammatically, a compressor 1, for compressing the gas preliminary to its liquefaction, as hereinafter described. The compressed gas is cooled by any suitable cooling dev ce 2, as for instance a water cooler, which extracts the heat of compression therefrom. From the cooling device 2, the compressed passes into a passage 3 of a heat exchanger, designated as a whole by the numeral 4. A portion of the gas in passage 3 is led to an expansion engine 5, expanded therein and returned to the cold end of a second passage 6 of the heat exchanger 4, as shown by the arrows, Fig. 1. Said expansion engine 5 and passage 6 are part of an external cooling agency; the circulation of a portion of the working fluid through such agency is utilized in extracting a portion of the heat from the incoming compressed fluid in the passage 3, and in offsetting the inleakage of atmospheric heat, in the manner common to liquefying processes at present in use.

The lower end of the passage 3 serves as a container for a quantity of the working fluid which is liquefied within said passage in the manner hereinafter set forth; there is no escape for such liquid to the return circuit of the systemexcept through a pump 7, which delivers the liquid into a third passage 8 of the heat exchanger 4 at a pressure higher than the pressure in passage 3. The pressure prevailing in the passage 8 is obviously due to the resistance imposed against the outflow of vapor from the upper end of said passage; in forcing liquid into the bot tom of this passage, the pump 7 must put it under sufficient pressure to overcome the pressure prevailing therein, which, as above stated, is higher than the pressure prevailing in passage 3. The heat exchange between the fluids in passages 3 and 8, in a manner similar to that well known in apparatus of this character, entails the discharge of high pressure fluid from the top or warm end of passage 8 at substantially the temperature of the gas entering the interchanger at the top or warm end of passage 3; the substantial equalization of tempera tures at any given level by heat interchange between the two passages 3 and 8, is contemplated, and in common with other apparatus of this character, the temperatures are lower, the lower the level reached in said interchanger. In said passage 8, the liquid is evaporated and has its temperature raised, in the manner hereinafter particularly described; from the passage 8 the highly compressed evaporate may be led, as described in the aforesaid copending application of Jefleries, either with or without the addition of external heat to a motor 9 wherein it may be used to develop a portion of the power for driving the compressor 1. If: de sired, the gas exhausted from said motor and the gas from the external cooling agency leaving the warm end of the passage 6 of the interchanger may be returned to the inlet of the compressor 1, recomprcsscd therein and passed again through the same circuits.

Assuming the establishment of the conditions illustrated in Fig. 1, wherein the broken lines indicate the presence of the working fluid in a liquefied state. which cond'ition may be attained, if' desired, by the operation of the external cooling agency above described, it will be especially clear if the fluid dealt with is a simple gas, that the natural interchange of heat between the cold compressed gas at the point of liquefaction in passage and the liquid in passage 8 will not effect the liquefaction of said in passage 3, nor will it effect the evaporation of said liquid in passage 8, since the condensation temperature in passage 3 is lower than the boiling temperature in passage 8. owing to the difference in inres-=ure produced by the pump 7. The transter of the latent heat of condensationfrom the vapor being condensed above surface av to evaporate the liquid at Z), is effected in the manner shown in Fig. 2, wherein 10 represents a coil immersed in the liquid formed within the pas sage 3 of the interchanger and 11 represents a pump or compressor interposed between said coil 10 and a coil 12 immersed in the liquid contained within the pas-=age 8 of the inter-changer. Said coil l2 ommunicates with an expander or nozzle 13, and the latter is connected to the inlet side of the coil ll). thereby forming a closed circuit. Said circuit may be supplied with a circulating fluid having a boiling point at the same or a lower temperature than the fluid to be condensed. at the surface a. Assuming that the compressor 11 Works at a slightly higher pressure than the pump 7, and that the fluid used in said circuit is the same as the Working fluid, it will be clear that the circulation by -onipressor ll, during a given period, of a weight of fluid equal to or slightly in excess of the weight of win-king fluid entering passage 3 during the same period, will effect this transfer of heat contents, as follows The fluid passing to coil 10, after its pressure is released in nozzle 13. may be mostly liquid, and while condensing the fluid above surface a, by extracting the latent heat of condensation therefrom it may be only partly evaporated. The mixture of liquid and vapor from the coil l0, passing to the compressor 11, has its pressure and temperature raised by said compressor. Passing in substantially gaseous form to the coil 12. it effects the evaporation of liquid at the surface 5, by transfer of its heatto said liquid, and is itself condensed thereby, in whole or in part. The subsequent release of pressure from said circulating fluid in the nozzle 13 and the consequent recooling thereof, causes its return to the coil 10 in condition to re peat the (JOIltlQllrtltlOIl at the surface a, in the manner above described. The actions. above described, will be carried out, under the conditions assumed. very readily, merely by causing the liquid in coil if) to be slightly colder than the low pressure working vapor to be liquefied at this point, in order to promote the transfer of heatcontents in the proper direction; and it will be seen that the difference in temperature relied upon to effect this transfer of heat units between the fluids can be made as small a: desired simply by increasing the contact surfaces of the coil. The same is obviously true of the art-ion occurring in the high pressure passage 8. in which a slightly higher temperature within the coil l2 insures the necessary exchange of latent heats. it will oe clear that other conditions affecting the presure. temperature, coniposition. and quantity of the circulatory transfer fluid may be adopted, nithin a wide range, without departiin from the principles of the actions above set forth, since the foregoing assumptions were made merely for purposes of explanation. As has been shown. the transfer of the relatively large quantities of heat between the working and the circulating fluids occurs in each case with only a very slight temperature difference; that is to say, the absorption and rejection of latent heat by the working and circulating fluids, as described above, takes place under substantially constant temperature and hence with the highest possible elliciency.

The condensation of the fluid at the surface a is, therefore, secured by an evaporation of circulating fluid in the coil 10, and the evaporation of the liquid at the surface 6 is secured by a condensation of circulating fluid in coil 12. t is apparent that by the proper adjustment of the pressures in the coils 10 and 12, and of the quantity and nature of fluid circulated through said coils by the compressor 11, the relative pro ortion of liquid and gaseous content of the fluid in said coils may be controlled so as to attain the most efiicient transfer of latent heat of condensation from tae fluid in pussage 3 to the liquid in passage 8. namely. in such a manner that the quantity of fluid condensed at a may equal the quantity of liquid evaporated at b.

A modification of the transferring means. shown in Fig. involves the ornil'ion of the coil 12, the fluid from the compressor it being discharged directly into the liquid con tained in the passage 8. Under these circumstances, only liquid passes to the nozzle 13, While the compressor ll return: only vapor, which may be at a sulliciently high temperature to cause the evaporatimi of an equal amount of fluid from the liquid at 7), while being; itself completely condensed.

The return of the cold vaporized fluid through the passage 8 at a higher pressure than the incoming fluid in passage 3, secures a most efficient cooling of said incoming fluid, by reason of the increased specific heat of the returning fluid. Owing to its greater pressure and increased specific heat, said recvaporated fluid carries out from the system a greater amount of heat per degree of temperature exchanged than is brought in by the same weight of fluid from the compressor. As a result, the subsequent liquefaction of said incoming fluid, at the surface a, is effected with greater facility than in the processes now in ordinary use. Such liquefaction is promoted or Wholly brought about. by the above described transfer of the latent heat of condensation of the fluid in passa e 3 to the liquid in passage 8. The cooling which must be done by the refrige ating or expansion circuit containing the expansion engine 5 (which is not qualified for the most efficient heat extraction owing to the extremely low pressure of the cold gas returning in passage 6) is reduced to a minimum; however, the drop in temperature in the expansion engine 5, when the latter is suitably constructed, can be made so great as t cause a partial condensation fluid in the cxiiaust therefrom which may collected in the cold end of the passage 6. The added refrigerative effect resulting from the process may be utilized in various ways; cold vapor for refrigeration may be withdrawn at 14L, or liquid may be withdrawn at 15. By means of bypass 16 and valve 17, the liquid in passage 3 may be reduced in pressure and drawn out at 15, or the same may b drawn out, under pressure at 18.

It is to be understood that the process, as herein described, does not of necessity entail either the complete or the absolute liquefaction of the gaseous working fluid, and that the liquefaction liquid and liquelied .as used herein and .in the appended claims apply well to a condition of the fluid where in density and temperature it substantially approaches the liquid state. In such a condition said fluid is susceptible to a pressure increase by the expenditure of an almost negligible amount of power, which, together with the power required for initial compression is largely recoverable in the eflicient manner hereinbefore set forth.

The same of course holds true with respect to the changes in state undergone by the circulating latent heat transfer fluid, which, corresponding substantially in density and in coldness t the working fluid is compressed by the expenditure of an amount of work which is exceedingly small in comparison to the work of cooling that would otherwise have to be expended in the external cooling agency to remove the latent heat from the incoming working fluid.

In the application of the foregoing new principles, which differ radically and essentially from the principles underlying previous processes of this class, it is to be understood that my invention is in no sense limited to equivalents of the apparatus herein shown, said showing being wholly diagrammatic and illustrative and adapted solely for the purpose of simplifying the explanation of said broadly new principles.

I claim,

1. In a system of the class described, a reverse flow interchanger for the cooling and liquefaction of a gaseous working fluid, means for sustaining the pressure on the of be fluid in the return side of said interchanger,

and fluid circulating means for transferring latent heat from the fluid undergoing liquefaction to the liquid in said return side.

2. In a system of the class described, means for liquefying a gaseous working fluid comprising a reverse flow interchanger, means for increasing the pressure on the fluid in the return side of said interchanger, and fluid circulating means for transferring the latent heat of the fluid in the inlet side of the interclianger to the high pressure fluid in the return side of said interchanger.

8. In a system of the class described, means for passing a gaseous working fluid through he liquid state, means for increasing the pressure thereon while in the liquid state, and means for transferring latent heat from the fluid undergoing liquefaction to the liquid whose pressure has been raised, comprising a compressor and an expander for crculating a fluid in heat exchanging relation to the said two portions of the working fluid.

4:. In a system of the class described, means for passing a gaseous working fluid through the liquid state, means for increasing the pressure thereon while in the liquid state, and means for transferring latent heat from the fluid undergoing liquefaction to the liquid whose pressure has been raised, comprising a compressor and an expander for circulating a fluid in heat exchanging relation to the said two portions of the working fluid, and means for utilizing the evaporate from the high pressure liquid for the production of useful work iy expansion.

5. In apparatus of the character set forth, the combination with a reverse flow heat interchanger, for the countercurrent circulation of a gaseous working fluid, of means for increasing the heat absorbing capacity of the returning portion of said fluid in said interchanger and means for obtaining the liquefaction of the incoming fluid by the vaporization of the outgoing fluid.

6. In apparatus of the character set forth, the combination with means for progressively liquefying a gaseous working fluid, of means for circulating a fluid in heat exchanging relation to different portions of i he .vorking fluid, whereby to transfer latent heat to the liquefied portion from the porlion iiindergoing liquefaction without substantial change in temperature.

'7. In. apparatus of the character set forth, the combination with means for progressively liquefying a gaseous working fluid,

of means for circulating a fluid in heat exthe combination with means for progressively liquefying a gaseous working fluid, of means for raising the pressure of the liquefied portion. and fluid circulating means for extracting latent heat from the portion undergoing liquefaction and transferring said latent heat to the liquefied portion.

10. in apparatus of the cl'iaracter set forth. the combination with means for progressively liquefying a gaseous working fluid, of fluid circulating means for raising the pressure of the liquefied portion, means for extracting latent heat from the portion undergoing liquefaction and transferring said latent heat to the liquefied portion, and means for circulating the evaporate from said liquefied. portion, under increased pressure, in heat exchanging relation to the gaseous portion which is about to undergo liquefaction.

11. In an apparatus of the character set forth, the combination with means for circulating heat rejecting and heat absorbing portions of a working fluid in countercurrent, to eflect liquefaction thereof, of means for sustaining the pressure on said heatabsorbing portion, and fluid circulating means for transferring latent heat from said heat rejecting portion to said heat absorbing portion.

12. In apparatus for the cooling and liquefaction of a gaseous working fluid, means for circulating a fluid in heat exchanging relation to the working fluid undergoing liquefaction, to extract the latent heat of condensation therefrom, and means for circulating said first named fluid in heat exchanging relation to the liquefied working fluid, whereby to transfer said latent heat to the latter.

13. In apparatus for the cooling and liquefaction of a gaseous working fluid, means for circulating a fluid in heat exchanging relation to the working fluid undergoing liquefaction, to extract the latent heat of condensation therefrom. means for raising the pressure on said circulating fluid, and means for thereafter circulating it in heat exchanging relation to the liquefied portion of the working fluid.

14. In apparatus for the cooling and liquefaction of a gaseous working fluid, means for circulating a fluid in heat exchanging relation to the working fluid undergoing liquefaction, to extract the latent heat of condensation therefrom. means for raising the pressure on said circulating fluid, means for thereafter circulating it in heat exchanging relation to the liquefied portion of the working fluid, and means for expanding said circulating fluid prior to its return into heat exchanging relation to the work- :ing fluid undergoing liquefaction.

15, In apparatus for the cooling and liquefaction of a gaseous working fluid, means for circulating a fluid in heat exchanging relation to the working fluid undergoing liquefaction, to extract the latent heat of condensation therefrom, means for increasing the pressure of the liquefied work ing luid, and means for transferring said latent heat to the liquefied portion of the working fluid, under such increased pressure.

16. In apparatus for the cooling and liquefaction of a gaseous working fluid, means for circulating a fluid in heat exchanging relation to the working fluid undergoing liquefaction, to extract the latent heat of condensation therefrom, means for increasing the pressure of the liquefied working fluid, means for raising the pressure on said circulating fluid, and means for thereafter circulating it in heat exchanging relation to the liquefied portion of the working fluid whose pressure has been incl-c: scd.

17. in apparatus for the cooling and liquefaction of a gaseous working fluid. means for circulating a fluid in heat exchanging relation to the working fluid undergoing liquefaction, to extract the latent heat of condensation therefrom. means for increasing the pressure of the liquefied working fluid, means for raising the pressure 011 said circulating fluid. means for thereafter circulating it in heat exchanging relation to the liquefied portion of the working fluid whose pressure has been increased, and means for expanding said circulating fluid prior to its return into heat exchanging relation to the working fluid undergoing liquefaction.

18. In apparatus for the cooling and liquefaction of a gaseous working fluid, means for extracting heat from a portion of said fluid at a low temperature, and for transferring said heat to another port-ion of said fluid at a higher temperature.

1.). Tn apparatus for the cooling and liquefaction of a gaseous working fluid, fluid circulating means for extracting heat from a portion of said fluid and for transferring said heat to another port-ion of said fluid at a higher pressure.

20. In apparatus of the character set forth, means for extracting latent heat from a gaseous working fluid. to liquefy the same. fluid circulating means for transferring said latent heat to the liquefied portion of the working fluid, to evaporate the same, and means for maintaining said evaporate under sufficient pressure to enable it to perform useful work by expansion.

21. In apparatus of the character set forth, means for extracting latent heat from a gaseous working fluid, to liquefy the same, fluid circulating means for transferring said latent heat to the liquefied portion of the working fluid, to evaporate the same, and means for maintaining said evaporate under suflicient pressure to enable it to absorb heat usefully.

221m. apparatus for the cooling and liquefaction of a gaseous Working fluid, means for circulating a fluid in heat exchanging relation to said working fluid, to extract the latent heat therefrom, and means for vaporizing the liquefied working fluid by the heat absorbed by said circulating fluid.

23. In apparatus for the cooling and liquefaction of a gaseous Working fluid, means for circulating a fluid in heat exchanging relation to said working fluid, to extract the latent heat therefrom, and means for vaporizing the liquefied Working fluid by the heat absorbed by said circulating fluid under a sufiicient pressure to enable the evaporate from said working fluid to perform useful Work by expansion.

24.111 apparatus of the character set forth, means for passing a gaseous working fluid through the liquid state, and fluid circulating means for transferring latent heat from the gaseous portion undergoing liquefaction to the portion thereof Which is in the liquid state.

25. In apparatus of the character set forth, means for passing a gaseous working fluid through the liquid state, means for increasing the pressure thereon While in the liquid state, and fluid circulating means for transferring latent heatfrom the gaseous portion undergoing liquefaction to the liquid whose pressure has been raised.

26. In apparatus of the class described, the combination with means for circulating heat rejecting and heat absorbing portions of a working fluid in heat exchanging relation, of fluid circulating means for procuring the liquefaction of said heat rejecting portion by the vaporization of said heat'absorbing portion. 1

27.111 apparatus of the class described for the liquefaction of a gaseous Working fluid, the combination with means for sue taining the pressure on the liquid portion of the fluid, of fluid circulating means for procuring the liquefaction of the gaseous portion by vaporization of said liquid portion.

Dated this 22nd day of January, 1918. FRED E. NORTON. Witnesses 4 NELLIE \VHALEN, PENELOPE CoMBERBAoH. 

